Professional-grade water-soluble MAP delivering an industry-leading 61% phosphorus for exceptional flowering, fruiting, and root development. Dissolves completely for drip irrigation, fertigation, hydroponics, and foliar applications — unlike granular MAP, which is for soil use only.
At 61% P₂O₅, this water-soluble MAP delivers more available phosphorus per pound than virtually any other commercial fertilizer, maximizing return on every application.
Dissolves completely with no residue — safe for drip lines, injectors, and foggers. Unlike granular MAP 11-52-0, this technical-grade powder is engineered for liquid feed systems.
High phosphorus drives ATP energy transfer, flower initiation, bud formation, and fruit set — making MAP 12-61-0 the go-to choice for the transition into reproductive growth.
Phosphorus is critical for cell division and root elongation. Early-season MAP applications establish strong root architecture that supports the entire growing cycle.
MAP solutions have a pH of approximately 4.5, making this fertilizer ideal for alkaline soils and hard irrigation water where phosphorus availability is often limited by high pH.
Independently lab tested for heavy metal content to ensure crop purity and environmental safety. Technical-grade purity exceeds agricultural-grade MAP in dissolved clarity and consistency.
A primary phosphorus source in hydroponic nutrient solutions. Compatible with most hydroponic nutrients at 0.5–1.0 g per gallon — adjust pH after addition as MAP is acidic.
Registered with the California Department of Food and Agriculture. Meets all labeling and analytical requirements for commercial fertilizer sale and use in California and nationwide.
Dissolves at 1–2 lbs per 100 gallons for injection through drip systems. Delivers phosphorus directly to the root zone with no soil tie-up or granule breakdown lag time.
Precise liquid delivery minimizes phosphorus runoff versus broadcast granular application. Targeted fertigation means less product used, less leaching, and more efficient uptake.
Greenway Biotech sources technical-grade monoammonium phosphate produced by the controlled reaction of high-purity ammonia with food/technical-grade phosphoric acid. The result is a clean, white crystalline powder with superior solubility compared to agricultural-grade granular MAP.
Water-soluble powder grade — distinct from agricultural granular MAP 11-52-0, which does not dissolve and is intended for direct soil incorporation only. This technical grade is manufactured to higher purity standards for use in liquid feed systems, hydroponics, and foliar applications.
MAP 12-61-0 is formulated for applications where rapid, high-concentration phosphorus delivery is required. The 12% ammoniacal nitrogen works synergistically — the acidifying effect of ammonium lowers rhizosphere pH, which directly increases phosphorus solubility and uptake efficiency at the root surface.
All nitrogen is in ammonium (NH₄⁺) form — immediately available and taken up alongside phosphate ions. Ammonium also acidifies the root zone, enhancing phosphorus release from soil particles and improving overall micronutrient availability.
Among the highest phosphorus concentrations available in any water-soluble fertilizer. Phosphorus drives ATP energy production, cell division, DNA synthesis, and the signaling cascades that initiate flowering and fruit development.
MAP contains no potassium, allowing growers to supply phosphorus independently without altering potassium ratios. Pair with MKP 0-52-34 or Potassium Sulfate to complete a balanced program.
No granule breakdown required. Dissolved MAP delivers phosphate ions directly to roots on contact — critical during the narrow flowering window where phosphorus demand peaks within days.
Technical-grade purity means no insoluble fillers that clog emitters or injectors. Granular MAP 11-52-0 contains binders and coatings that make it unsuitable for any liquid delivery system.
Dissolve by weight for exact PPM targeting. Hydroponic and fertigation growers can maintain 150–200 ppm phosphorus in solution with consistent, measurable accuracy not possible with granular products.
| Area | Application Rate | Frequency |
|---|---|---|
| Per 100 square feet | 1–2 lbs | Every 4–6 weeks |
| Per Acre | 20–40 lbs | During growing season |
| Container Plants (5 gal) | 1–2 tablespoons | Every 2–3 weeks |
| Area | Application Rate | Frequency |
|---|---|---|
| Per 100 square feet | 2–4 lbs | Every 4–6 weeks |
| Per Acre | 40–80 lbs | As needed |
| Container Plants (5 gal) | 2–3 tablespoons | Every 2 weeks |
| Method | Rate | Best For |
|---|---|---|
| Drip Irrigation / Fertigation | 1–2 lbs per 100 gallons | Vegetables, orchards, commercial crops |
| Foliar Spray | 1–2 tbsp per gallon | Quick correction, transitional feeding |
| Hydroponics | 0.5–1.0 g per gallon; maintain 150–200 ppm P | Soilless systems — adjust pH after addition |
| Broadcasting (dissolved) | Dissolve, then apply 1–2 lbs per 100 sq ft | Field crops, lawns |
For flowering vegetables and fruits, begin increasing MAP rates 1–2 weeks before expected bloom. Phosphorus needs to be present in plant tissue before flowering begins — waiting until you see flowers means the window for maximum fruit set support has already partially closed.
Refer to the Safety Data Sheet (SDS) for complete safety information.
MAP 12-61-0 delivers phosphorus and a modest nitrogen boost — pair it with these products to build a complete, balanced nutrient program.
Adds fast-release nitrogen and essential calcium — the ideal companion for vegetative stages. Mix separately before combining to avoid precipitation.
Adds potassium to your phosphorus program without adding nitrogen. Ideal during late flower and fruit ripening when K demand is highest.
Provides sulfur alongside potassium to complete a P-K finishing formula for fruits, vegetables, and specialty crops.
Supplies magnesium and additional nitrogen. Magnesium is the central atom of chlorophyll — critical for photosynthesis efficiency alongside high-P feeding.
High phosphorus programs can reduce iron availability. Add chelated iron to prevent chlorosis in high-phosphorus fertigation programs.
Need phosphorus for direct soil incorporation or broadcasting? The granular version is designed for soil application where liquid systems aren't in use.
These are two different grades of monoammonium phosphate for different applications. MAP 12-61-0 is a technical-grade water-soluble powder that dissolves completely in water — it is designed for drip irrigation, fertigation, hydroponics, and foliar spray. MAP 11-52-0 is an agricultural-grade granular product for direct soil application only; it does not dissolve and will clog liquid delivery systems if you attempt to use it that way.
In terms of nutrient content, MAP 12-61-0 has slightly higher phosphorus (61% vs. 52%) and slightly lower nitrogen (12% vs. 11%) than the granular grade. Choose 12-61-0 for any liquid feed program, and MAP 11-52-0 for broadcasting or incorporating into soil.
MAP solutions have a pH of approximately 4.5 due to the acidic nature of monoammonium phosphate. In most cases this is actually beneficial — it helps dissolve calcium carbonate scale in hard water, improves phosphorus availability in alkaline soils (pH above 7.0), and keeps nutrients in their plant-available ionic form in the solution.
In hydroponics, monitor your reservoir pH after adding MAP and adjust back to your target range (typically 5.5–6.5). In drip fertigation, the final dilution in irrigation water usually brings the pH to an acceptable range, but test if you're working with already-acidic water or soils below pH 6.0.
Not in concentrated form. Phosphate ions (from MAP) and calcium ions (from calcium nitrate) react to form calcium phosphate, an insoluble white precipitate that will clog injectors, emitters, and tank outlets. Always use separate stock tanks for phosphorus-containing fertilizers and calcium-containing fertilizers.
When applying through a single irrigation line, inject each from a separate tank so they only mix in the highly diluted irrigation stream, where precipitation is no longer a risk. This is standard practice in commercial fertigation programs.
Phosphorus is the primary driver of reproductive growth in plants. It enables ATP production (the energy currency for all metabolic activity), supports cell division during rapid fruit development, and triggers the hormonal signaling that initiates flower bud formation. The 61% P₂O₅ concentration in MAP 12-61-0 is among the highest available in any water-soluble fertilizer, delivering maximum phosphorus per unit of product.
For best results, begin increasing MAP application rates 1–2 weeks before expected flowering to build phosphorus reserves in plant tissue before the bloom window opens.
Yes — MAP 12-61-0 is commonly used as a phosphorus source in hydroponic nutrient solutions at 0.5–1.0 grams per gallon. Because it is acidic, always measure and adjust pH after adding MAP to your reservoir. Maintain 150–200 ppm phosphorus in solution for most crops during vegetative and early flowering stages.
Important: add MAP to the reservoir before any calcium-containing nutrients to prevent localized precipitation during mixing. Always pre-dissolve MAP in water before adding to the main reservoir.
High phosphorus levels in solution or soil can suppress the uptake of zinc, iron, and manganese by competing for the same transport sites in roots. This is particularly relevant in high-P fertigation programs where EC and phosphorus levels are elevated for extended periods.
Monitor plants for signs of iron or zinc deficiency (interveinal chlorosis, small new leaves) during intensive MAP programs and supplement with Chelated Iron EDTA or Chelated Zinc EDTA as needed. Staying within recommended rates significantly reduces this risk.
We stand behind the quality of our MAP 12-61-0 Water-Soluble Fertilizer. If you're not completely satisfied with your purchase, we offer a 90-day money-back guarantee. Simply return the unused portion in its original packaging and we'll process a full refund, no questions asked.
At Greenway Biotech, we believe in giving back to our community. 1% of all profits from our product sales go to the Greenway Foundation, dedicated to supporting children's education. Your purchase contributes directly to improving educational opportunities for children.
For more information, visit greenway.foundation.
Check out our full FAQ page or contact our experts for personalized advice.
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